Data-Discs have released Shinobi III: Return of the Ninja Master digitally on their Bandcamp page, joining their existing catalogue with many SEGA soundtracks.
Bandcamp: https://datadiscs.bandcamp.com/album/shinobi-iii-return-of-the-ninja-master-remastered
Price is £6 ( ~7€ / ~$8 ) and offers streaming in MP3 as well as digital download in lossy and lossless formats, ranging from MP3 to AIFF. This is the same soundtracks, that Data-Discs has previously released on vinyl records.
There will be also a very small leftover sale on Saturday 11th June at 6:00pm BST (that’s 10:00am PDT / 1:00pm EDT), including titles like Altered Beast, Radiant Silvergun and Shadow Dancer, as well as B-Stock of Metal Gear 2: Solid Snake. This is currently limited to Data-Discs newsletter subscribers. If there will be any remaining stock, it will be available to general public.